With equipment in a plant and the like, there are cases wherein, as a field apparatus that measures a physical quantity, such as pressure, flow volume, and temperature, a field apparatus is used that operates a circuit using an internal battery and both measures a physical quantity and performs data communication to provide notification of the measurement value. See, for example, Japanese Unexamined Patent Application Publication No. 2009-133755.
In a field apparatus that operates on a built-in battery of this type, it is necessary to replace the built-in battery in accordance with the lifespan of the built-in battery, and therefore a maintenance workload arises.
The maintenance of a field apparatus in a plant involves the planning of production, the adjustment of schedules, the procurement of replacement equipment, and the securing of maintenance work personnel and staffing, and consequently the burden and cost of plant management related to the performance of maintenance each time is large. Consequently, while it is desirable to avoid the risk of production stoppages owing to mechanical failures, it is also desirable to, as much as possible, not perform unnecessary maintenance work and to reduce the number of times that maintenance is performed. Accordingly, in order to perform maintenance wherein parts, such as batteries, are replaced efficiently all at once, it is preferable that the lifespans of replacement parts are well defined and that the lifespans of multiple replacement parts are in sync.
However, there are uncertainties in the lifespans of batteries, and it is also often the case that batteries cannot be used for the full life defined in the specification of the batteries. Consequently, to reduce production risk, the plant manager either replaces batteries based on a period that is shorter than the lifespan, or identifies the lifespan of each individual battery, determines an appropriate timing for the replacement of each battery, and replaces the batteries accordingly. In the case of the former, even a battery that has not yet reached the end of its life and therefore does not need to be replaced is also replaced. Moreover, in the case of the latter, it is troublesome to identify the lifespan of each individual battery. Accordingly, in either case, the number of times that maintenance is performed increases, and the workload associated therewith increases, which are problems.
The present invention is conceived in order to solve such problems, and it is an aspect of the present invention to provide a field apparatus that can reduce the workload needed to perform the maintenance of batteries.